Speaking valves are well-known in prior art. For example, they are attached to a tracheostomy tube or tracheostomy patch, so that people without vocal cords can speak by means of a voice prosthesis. By activating the speaking valve, air is guided through a voice prosthesis, which is arranged in a fistula between the trachea and the esophagus. Even if the vocal cords are still available, it is important that the air does not escape from the tracheal tube before it reaches the vocal cords.
From U.S. Pat. No. 4,582,058A it is known to close a speaking valve by means of a pressure impulse effected by the patient's breathing, thus allowing the person to speak. However, these valves proved to be not very reliable.
WO 95/17138 A proposes to combine the speaking valve with an artificial nose. This artificial nose is a filter which absorbs moisture and heat from the exhaled air and which moistens and heats the air streaming into the tracheal tube.
EP 1 077 658 B1 describes a vocal valve having a filter, wherein the vocal valve comprises an elastic housing or elastic valve element and the housing or valve element can be deformed, for example, by means of finger pressure, in such a way that a housing part is pushed on a valve seat and the valve is closed.